Anti-theft devices which attach to an automobile steering wheel have been in use for a long time, having different structure to attain the object. One main structure has an elongated body member having a passageway for an elongated rod member to extend adjustably in the body member. The rod member is adapted to move in telescoping fashion in the passageway of the body member along the axis, for two hooks to engage the inside portion of the steering wheel and the rod member is locked stationary at any of a plurality of positions so as to prevent the steering wheel from being rotated.
Another structure has an elongated body member with one of its ends attached to a steering wheel and the other of its ends extending to some place in an automobile to prevent the steering wheel from being rotated.
Another structure has a curved plate with one of its ends attached to a steering wheel, the plate body passing through the steering wheel and the other of its ends extending on a gauge panel board to prevent the steering wheel from being rotated.
The first and second devices cannot completely hamper a steering wheel from rotation, and can allow it to move up and down, so particular consumers may be unable to be satisfied with such devices.
The third one can limit a steering wheel to rotate in a scope smaller than the first and the second ones, but has comparatively large dimensions to operate, and in addition, the curved extending portion of the curved plate is liable to be straightened to be broken.